1) Field of the Invention
This invention relates generally to fabrication of nitride and oxynitride film for semiconductor devices and more particularly to the fabrication of a silicon nitride layer and an oxynitride layer used a bottom anti-reflective coating (BARC) for fabrication semiconductor devices.
2) Description of the Prior Art
As technology scaled down to 0.25 .mu.m or below, the photolithography is pushed to deep UV generation. The reflection of the incident light from the photoresist-substrate interface increases, leading to a severe line width fluctuation as the resist thickness varies with topography and also the notching in normally unexposed areas by the reflected light.
Various methods have been explored to reduce the light reflections. Bottom anti-reflective coating (BARC) appears to be the most practical approach. Many BARC layer are organic layers that are spun on. However, the organic BARC layers increase the cost significantly and cause following etching process stringent. Improved processes must be developed better form BARC layers to are less complex to manufacture.
The importance of overcoming the various deficiencies noted above is evidenced by the extensive technological development directed to the subject, as documented by the relevant patent and technical literature. The closest and apparently more relevant technical developments in the patent literature can be gleaned by considering U.S. Pat. No. 5,523,255(Hyung) shows a method for forming a Silicon oxynitride layer for a LOCOS process. U.S. Pat. No. 5,478,765(Kwong et al.) shows process for forming a Silicon oxynitride layer. Therefore, there is a need for improved processes to better form BARC layers that are less complex to manufacture.